An FDA rule effective Aug. 5 states that foods may be labeled "gluten free" only if there's less than 20 parts per million of the protein. James Benet/iStockphoto hide caption

itoggle caption James Benet/iStockphoto

About 40 years ago wheat breeders introduced new varieties of wheat that helped farmers increase their grain yields. But scientists say those varieties aren't linked to the rise in celiac disease. Karen Bleier/AFP/Getty Images hide caption

itoggle caption Karen Bleier/AFP/Getty Images

More and more gluten-free beers are entering the marketplace. We asked a librarian with celiac disease for her list of favorites. Bill Chappell/NPR hide caption

itoggle caption Bill Chappell/NPR